Loosely grouped under three intriguing categories (""Parents,"" ""Autonomy"" and ""Collaborations""), Ambition & Love in Modern American Art tracks definitions of significant art as they changed over the 20th century. In looking for what shapes significance, artist Jonathan Weinberg (Speaking for Vice) focuses on the role of ambition, celebrity and desire, the forces of public life outside the artist's studio, and their inevitable encroachment on what happens within it. His nine loosely connected essays examine the works and lives of Whistler, Jackson Pollock, Sally Mann, Jean-Michel Basquiat and others. But rather than capturing and isolating some element of timeless significant form, Weinberg suggests that an artist's real talent ""is a matter of convincing others that you are talented."" ( June 19)